JP2017503995A - Variable operating point components of ice cube ice machine - Google Patents

Abstract

An ice making machine that forms ice during a cooling cycle, the ice making machine having a variable speed compressor, a condenser, and an evaporator, wherein the variable speed compressor, the condenser, and the evaporator are one or more. The refrigerant line is in fluid communication. The ice maker controls the speed of the variable speed compressor based on the ice tray thermally coupled to the evaporator, the feed pump, the detection device that identifies the state of the cooling cycle, and the state of the identified cooling cycle And a controller adapted to do so. The ice maker may also include a variable speed condenser fan that can be controlled by the controller based on the identified state of the cooling cycle. Further, the feed pump may be a variable speed feed pump that can be controlled by the controller based on the identified state of the cooling cycle. [Selection] Figure 1

Description

[Reference to related applications]
This application claims priority from US Provisional Patent Application No. 61 / 924,907, filed Jan. 8, 2014, the entire contents of which are hereby incorporated by reference.

The present invention relates generally to automatic ice makers, and more particularly, includes a variable operating point component including a variable speed feed pump and a cooling system having a variable speed compressor and a variable speed condenser fan. Related to ice making machines.

An ice making machine that employs an ice tray in which a cubic mold has a lattice shape and has a water flow and ice collection by gravity is well known and widely used. Such machines are widely accepted and are particularly desirable for commercial facilities where the demand for fresh ice is always high, such as restaurants, bars, motels and various beverage retailers.

In these ice making machines, water is supplied to the upper part of the ice tray, and the ice tray directs the water to a winding path toward the water supply pump. As soon as some of the supplied water accumulates in the ice tray, freezes into ice, and is identified as adequately frozen by appropriate means, the ice tray is defrosted, the ice melted a little, and the ice tray To the bottle. Typically, these ice makers can be classified according to the type of ice they produce. One such type is a lattice ice maker. A lattice-type ice maker produces approximately square ice cubes that are formed within the individual lattices of the ice tray, and the ice cube is the next continuous sheet of ice cubes when the ice thickness exceeds the ice tray thickness. After that, when the ice cube sheet falls into the bottle, it breaks into individual ice cubes. Another type of ice machine is an individual ice cube ice machine. This ice making machine produces approximately square ice cubes that are formed within individual lattices of an ice tray, and does not form a continuous sheet of ice cubes. Therefore, when ice is collected, individual ice cubes fall from the ice tray to the bottle. The control device controls the operation of the ice making machine to ensure that ice is supplied constantly.

A typical ice maker cooling cycle consists of two sub-cycles: a sensible cooling cycle latent cooling cycle. During the sensible cooling cycle, the supplied water is continually cooled by recirculating through the ice tray and returning to the feed pump. When the supplied water reaches the freezing point, it begins to freeze in the ice tray, the latent heat cooling cycle begins, and the amount of water that falls from the ice tray and returns to the feed pump decreases gradually as ice forms in the ice tray. To do.

Conventionally, the main components of a cooling system used in an ice maker include a refrigerant that sequentially flows through a compressor, a condenser, a thermal expansion valve, and an evaporator. The evaporator is thermally coupled to an ice tray to freeze the supplied water into ice. However, the cooling load at any given time during the sensible cooling cycle is driven by the water temperature, and the cooling load at any given time during the latent cooling cycle depends on the ice layer thickness of the ice tray. Mainly driven. As the water temperature decreases during the sensible heat cooling cycle, and as the ice thickness of the ice tray increases during the latent heat cooling cycle, the cooling load on the ice making machine decreases accordingly throughout the cooling cycle.

Briefly, therefore, one aspect of the invention relates to an ice making machine that produces ice during a cooling cycle. The ice making machine includes a variable speed compressor, a condenser, and an evaporator, and the variable speed compressor, the condenser, and the evaporator are in fluid communication with one or more refrigerant lines. The refrigerant flows through one or more refrigerant lines. The ice maker further comprises an ice tray thermally coupled to the evaporator, a water supply pump for supplying water to the ice tray, and a controller adapted to control the speed of the variable speed compressor during the cooling cycle. Prepare.

Another aspect of the invention relates to an ice maker that produces ice during a cooling cycle. The ice making machine includes a variable speed compressor, a condenser, and an evaporator, and the variable speed compressor, the condenser, and the evaporator are in fluid communication with one or more refrigerant lines. The refrigerant flows through one or more refrigerant lines. The ice making machine includes an ice tray thermally coupled to the evaporator, a feed pump for supplying water to the ice tray, a first speed during a sensible heat cooling cycle, a second speed during a latent heat cooling cycle, and a sampling. And a controller adapted to operate the variable speed compressor at a third speed during the ice cycle.

Another aspect of the invention relates to an ice maker that produces ice during a cooling cycle. The ice making machine includes a variable speed compressor, a condenser, and an evaporator, and the variable speed compressor, the condenser, and the evaporator are in fluid communication with one or more refrigerant lines. The refrigerant flows through one or more refrigerant lines. The ice maker is based on an ice tray that is thermally coupled to the evaporator, a water pump that feeds the ice tray, a detection device adapted to identify the status of the cooling cycle, and the status of the identified cooling cycle. And a controller adapted to control the speed of the variable speed compressor.

Yet another aspect of the invention relates to an ice making machine further comprising a variable speed condenser fan. The controller is adapted to further control the speed of the variable speed condenser fan based on the identified cooling cycle condition.

Yet another aspect of the invention relates to an ice maker, wherein the feed pump is a variable speed feed pump and is further adapted to control the speed of the variable speed feed pump based on the state of the cooling cycle identified by the controller. .

Yet another aspect of the invention relates to an ice making machine having a cooling system that makes ice using a refrigerant capable of transitioning between a liquid state and a gas state. The ice making machine includes a variable speed compressor, a condenser, a thermal expansion element, and an evaporator. The ice maker controls the speed of the variable speed compressor based on the ice tray thermally coupled to the evaporator, the feed pump, the detection device that identifies the state of the cooling cycle, and the state of the identified cooling cycle And a controller adapted to do so.

Yet another aspect of the invention relates to a method of controlling an ice maker that produces ice during a cooling cycle. The ice making machine includes a variable speed compressor, a condenser, and an evaporator. The variable speed compressor, condenser, and evaporator are in fluid communication by one or more refrigerant lines. The refrigerant flows through one or more refrigerant lines. The ice maker is based on an ice tray that is thermally coupled to the evaporator, a water pump that feeds the ice tray, a detection device adapted to identify the status of the cooling cycle, and the status of the identified cooling cycle. And a controller adapted to control the speed of the variable speed compressor. The method identifies an ice machine cooling cycle condition, calculates a desired compressor speed for a variable speed compressor based on the identified cooling cycle condition, and calculates a desired compression speed for the variable speed compressor. Changing the mass flow rate of the refrigerant by changing to the machine speed.

Yet another aspect of the invention relates to a method of controlling an ice making machine having a cooling system that makes ice using a refrigerant capable of transitioning between a liquid state and a gas state. The ice making machine includes a variable speed compressor, a condenser, a thermal expansion element, an evaporator, an ice tray thermally coupled to the evaporator, a water supply pump, and a detection device that identifies the state of the cooling cycle. A controller adapted to control the speed of the variable speed compressor based on the identified state of the cooling cycle. The method identifies an ice machine cooling cycle condition, calculates a desired variable speed compressor speed based on the identified cooling cycle condition, and sets the variable speed compressor speed to a desired compressor speed. Changing the mass flow rate of the refrigerant.

These and other features, aspects, and advantages of the invention will become more apparent from the following detailed description, claims, and accompanying drawings. The drawings illustrate features according to exemplary embodiments of the invention.

1 is a schematic diagram of an ice making machine having a variable operating point component and a control device that uses a pressure sensor to identify the state of a cooling cycle and controls the operating point of the variable operating point component according to an embodiment of the invention. It is. It is the schematic of the control apparatus which controls the variable operating point component of an ice making machine. 1 is a cross-sectional view of a sump with a fitting that allows measurement of the sump water pressure, according to one embodiment of the invention. FIG. 4 is a flowchart illustrating the operation of an ice making machine having a cooling system with variable operating point components controlled by a control device, according to one embodiment of the invention. According to one embodiment of the invention, a variable operating point component, a control device that identifies the state of the cooling cycle using a pressure sensor and controls the operating point of the variable operating point component, an inter-refrigerant heat exchanger, It is the schematic of the ice making machine which has. According to one embodiment of the invention, a variable operating point component, a controller that identifies the state of the cooling cycle using a pressure sensor, controls the operating point of the variable operating point component, and identifies the state of the cooling cycle 1 is a schematic view of an ice maker having a cooling system with additional sensors. FIG. An ice making machine comprising: a variable operating point component according to an embodiment of the invention; and a controller for identifying the state of a cooling cycle using a temperature sensor and a pressure sensor and controlling the operating point of the variable operating point component FIG. 4 is a flowchart illustrating the operation of an ice making machine having a cooling system with variable operating point components controlled by a control device, according to one embodiment of the invention. According to one embodiment of the invention, a variable operating point component, a control device, a first temperature sensor for measuring an inlet temperature of refrigerant entering the evaporator, and a second temperature for measuring an outlet temperature of refrigerant exiting the evaporator FIG. 2 is a schematic view of an ice maker having a sensor and the controller is adapted to control the operating point of the variable operating point component in response to the measured inlet and outlet temperatures. 4 is a flowchart illustrating the operation of an ice making machine having a cooling system with variable operating point components controlled by a control device, according to one embodiment of the invention. A cooling cycle using a variable operating point component, a temperature sensor that measures the temperature of the refrigerant in the suction line, a pressure transducer that measures the pressure of the refrigerant in the suction line, and a pressure sensor according to an embodiment of the invention FIG. 2 is a schematic view of an ice making machine having a control device that identifies the state and controls the operating point of the variable operating point component. A variable operating point component according to an embodiment of the invention, a temperature sensor that measures the temperature of the refrigerant in the suction line, a pressure transducer that measures the pressure of the refrigerant in the suction line, a temperature sensor that measures the water temperature, and a pressure 1 is a schematic view of an ice making machine having a controller that uses a sensor to identify the state of a cooling cycle and control the operating point of a variable operating point component.

Before the embodiments of the invention are described in detail, it should be understood that the invention is not limited to the details and the arrangement of components shown in the following description and the following drawings. The invention is capable of other embodiments and of being practiced or carried out in various ways. Also, it is to be understood that the wordings and terms used herein are for illustrative purposes and should not be considered limiting. The use of “including”, “comprising”, “having” and variations thereof herein is meant to include the items listed thereafter, equivalents thereof, and additional items. It should be understood that all numbers representing measurements and the like used in the specification and claims are all modified in part by the word “about”. In the present specification, front and rear, left and right, top and bottom, upper and lower are for convenience of description, and the invention disclosed in this specification and its components are arranged in any one position or direction of space. Note that this is not a limitation.

Variable Operating Point Components Changing During Latent Heat Cooling Conventional ice machine cooling systems are typically sized to maximize cooling capacity. However, the variation in the cooling load during the sensible heat cooling cycle is smaller than the variation in the cooling load during the latent heat cooling cycle. Thus, for most of the cooling cycle, the components associated with the compressor are significantly too large for the system, resulting in reduced operating efficiency and an unnecessarily large pressure differential.

Thus, an improved ice maker with variable operating point components comprising, in various embodiments, a combination of a variable speed feed pump, variable speed compressor, variable speed condenser fan, and thermostat or electronic thermal expansion valve. Describe. The variable operating point component can be controlled based on the state of the cooling cycle to improve efficiency. In various embodiments, for example, the variable operating point component operates at approximately one operating point during the sensible heat cooling cycle and operates at the variable operating point as the cooling load decreases during the latent heat cooling cycle. In other embodiments, for example, the variable operating point component operates at a variable operating point during the sensible cooling cycle and during the latent cooling cycle. In still other embodiments, for example, the variable speed compressor can operate at a variable speed during a sensible heat cooling cycle, a latent heat cooling cycle, and / or during an ice collection cycle. By operating a variable operating point component at a variable operating point in one or more of a sensible cooling cycle, a latent cooling cycle, and an ice-collecting cycle, the energy is compared to a single operating point component. Increase efficiency and save energy.

FIG. 1 shows several main components, including variable operating point components, according to one embodiment of an ice maker 10. Here, the variable operating point may include a variable speed. The ice making machine 10 includes a variable speed compressor 12, a condenser 14 that condenses the compressed refrigerant vapor discharged from the variable speed compressor 12, a variable speed condenser fan 15, and heat that lowers the temperature and pressure of the refrigerant. An expansion element 18 and an evaporator 20 are provided. Thermal expansion element 18 may include, but is not limited to, a capillary tube, a thermostat expansion valve, or an electronic expansion valve. The ice making machine 10 also includes an ice tray 60 that is thermally coupled to the evaporator 20. The ice tray 60 may be provided with a large number of depressions (usually in the form of lattice cells) where water flowing on the surface accumulates on the surface. Water is pumped from a sump 64 by a variable speed feed pump 62 and exits a distribution manifold or tube 66 through a water supply line 63, impinges on the ice tray 60, flows over a recess in the ice tray 60, and freezes. Become ice. The sump 64 may be located below the ice tray 60 and receives all the water falling from the ice tray 60 and the water is recirculated by the variable speed feed pump 62. The ice tray 60 described herein may include any number of types of molds that produce a continuous sheet of ice cubes, separate ice cubes, and / or different types of ice cubes. Furthermore, embodiments of the invention can be adapted to various types of ice machines (eg, lattice type, separate ice cube type) and other, though not specifically, other ice machines without departing from the scope of the invention. .

The variable speed compressor 12, the variable speed condenser fan 15, and the variable speed feed water pump 64 are each driven by a variable speed motor (not shown). Each variable speed motor of variable speed compressor 12, variable speed condenser fan 15, and variable speed feed pump 64 is a continuously variable speed motor adapted to operate at any speed within a set of speeds. It is desirable. Such a variable speed motor may be an electronic commutation motor (“ECM”). Alternatively, each variable speed motor of the variable speed compressor 12, variable speed condenser fan 15, and variable speed feed water pump 64 may be at a plurality (eg, 2, 3, 4, or more) specific speeds. A motor adapted to operate may be included.

The ice making machine 10 may include a temperature sensitive cylinder 26 disposed at the outlet of the evaporator 20 to control the thermal expansion element 18. In other embodiments, when an electronic expansion valve 118 (see FIGS. 11 and 12) is used, the temperature sensor 25 and pressure transducer 29 are used in place of the temperature sensitive cylinder (see FIGS. 11 and 12). The temperature sensor 25 and the pressure converter 29 may provide the temperature value and pressure value of the refrigerant in the suction line 28d to the control device 80, respectively. Then, the control device 80 can control the opening of the electronic expansion valve 18 based on the temperature and pressure. When the ice reaches the desired thickness, the hot gas valve 24 directs warm refrigerant from the variable speed compressor 12 directly to the evaporator 20 to remove or collect ice cubes from the ice tray 60. The ice making machine 10 may also include an ice collection sensor switch (not shown) known in the art. The ice collection sensor switch detects when ice falls from the ice tray 60 so that the control device 80 can stop ice collection and start making ice. As described in more detail elsewhere herein, some form of refrigerant circulates through these components via lines 28a, 28b, 28c, 28d. The ice making machine 10 may have other conventional components not described herein, including a water source, ice bottle, and power source.

The ice making machine 10 may also include a control device 80. The control device 80 is preferably arranged away from the evaporator 20 and the water reservoir 64. As shown in FIG. 2, the control device 80 includes a processor 82 that controls the operation of the ice making machine 10. The controller 80 may also include or be coupled to the pressure sensor 84. The pressure sensor 84 may be used to correlate the water pressure in the sump 64 with the ice thickness of the ice tray 60 to identify the state of the cooling cycle during the latent heat cooling cycle of the ice making machine 10. The pressure sensor 84 may be a monolithic silicon pressure sensor that can output a signal proportional to the pressure of the water in the water reservoir 64 to the processor 82. Using the output from the pressure sensor 84, the processor 82 can determine the state of the cooling cycle based on the amount of water turned to ice. During the latent heat cooling cycle, as the ice thickness of the ice tray increases, the cooling load may decrease, so the controller 80 may configure the variable operating point configuration of the ice making machine 10 based on the state of the cooling cycle with respect to the cooling load. Calculate and set the operating point of an element. Therefore, the efficiency of the ice making machine 10 may be improved using the variable speed compressor 12. The variable speed compressor 12 can change the mass flow rate of the liquid refrigerant based on the state of the cooling cycle. For example, if the ice thickness on the ice tray 60 increases during the cooling cycle, the mass flow rate of the liquid refrigerant can be reduced. The use of the pressure sensor 84 also allows the processor 82 to determine the appropriate time for the start of the ice collection cycle and to control the water injection and purge functions. In some embodiments, the pressure sensor 84 may be a pressure transducer, such as part number MPXV5004 manufactured by Freescale Semiconductor, Austin, Texas.

With reference to FIGS. 2 and 3, an embodiment of the control system air fitting 90 and pneumatic tube is described in detail. In some embodiments, the barometric sensor 84 may be connected to the sump 64 by an air line 86 having a proximal end 86a and a distal end 86b. The proximal end 86a of the air feed tube 86 is connected to the atmospheric pressure sensor 84, and the distal end 86b of the air feed tube 86 is connected to the air fitting 90 and is in fluid communication. The air fitting 90 may be disposed within the sump 64 and includes a base 90a, a first portion 90b, a second portion 90c, and a top 90d, all in fluid communication with the bottom 72 of the sump 64. . The base 90a, the first portion 90b, the second portion 90c, and the top 90d of the air fitting 90 define a chamber 92 that can trap air. One or more openings 98 surround the base 90a to allow fluid communication between the bottom 72 of the sump 64 and the air in the chamber 92 of the air fitting 90. As the water level in the sump 64 increases, the pressure at the bottom 72 of the sump 64 is transferred to the air in the chamber 92 through one or more openings 98 in the air fitting 90. The air pressure in the chamber 92 increases, and this increase in air pressure is transmitted to the air pressure sensor 84 through the air in the air pipe 86. In this way, the control device 80 can determine the water level of the water reservoir 64. Therefore, when the water level of the water reservoir 64 decreases, the pressure in the chamber 92 also decreases. This pressure drop is transmitted to the air pressure sensor 84 via the air in the air pipe 86. In this way, the control device 80 can determine the water level of the water reservoir 64.

The base 90a of the air fitting 90 may be substantially circular and may have a large diameter to help reduce or eliminate the capillary action of water in the chamber 92. The first portion 90b may be substantially conical and thus transitions from a larger diameter of the base 90a to a smaller diameter of the second portion 90c. The second portion 90c may gradually become thinner from the first portion 90b toward the top 90d. Arranged near the top 90d may be a connector 94 that connects the tip 86b of the airpipe 86. The connector 94 may be any type of pneumatic tube connector known in the art, including but not limited to barbs, nipples, and the like.

By placing the pressure sensor 84 on the controller 80 located remotely, the pressure sensor 84 is not placed in the food zone. With such an arrangement, the atmospheric pressure sensor 84 does not come into contact with water, so that it is not affected by minerals and scales that can be left by the supplied water. Furthermore, since the barometric sensor 84 is not in contact with water, it is not affected by the electrical properties of the water, and therefore the thickness of the ice of the deionized water supplied and the water with a high mineral content using the barometric sensor 84 is not affected. Can be determined. Further, in some embodiments, the atmospheric pressure sensor 84 does not have a movable part, and thus is not easily affected by inconsistency in the arrangement within the ice making machine 10 and changes over time of the ice making machine 10. In some embodiments, the position of barometric sensor 84 and the position of air fitting 90 are not adjustable. Thus, in various embodiments, the thickness of ice, the amount of water in the sump 64, and the amount of water used in each cycle can be measured, controlled, and adjusted electronically. In other embodiments, the control device 80 may comprise any commercially available device that measures the water level in the sump 64 in addition to or instead of the pressure sensor 84, or such device. May be connected to.

The control device 80 includes a processor readable medium, and the processor readable medium stores codes representing instructions that cause the control device 80 to perform processing. The controller 80 may be, for example, a commercially available microprocessor, application specific integrated circuit (ASIC), or a combination of ASICs, which perform one or more specific functions, or one or more. Designed to enable specific devices or applications. In yet another embodiment, the controller 80 may be an analog or digital circuit, or a combination of multiple circuits. The controller 80 may also include a memory component that stores data in a form readable by the controller 80. The controller 80 can store data in the memory component or can read data from the memory component.

With reference to FIGS. 1 and 2, the controller 80 includes a variable speed compressor 12, a variable speed condenser fan 15 and a variable speed compressor 12 external to the controller 80 via input / output (I / O) components (not shown). Components that communicate with the variable speed feed pump 62 may also be provided. In other embodiments, for example, the controller 80 may include a water supply valve (s) (not shown), a water purge valve (s) (not shown), a hot gas valve 24, and / or Other input / output (I / O) components may be provided that communicate with and / or control the thermal expansion element 18, where the thermal expansion element may be an electronic expansion valve. In other embodiments, for example, the controller 80 includes other inputs / communications with various sensors and / or switches including, but not limited to, pressure transducers, temperature sensors, acoustic sensors, ice collection switches, and the like. An output (I / O) component may be provided. According to one or more embodiments of the invention, the I / O component may include a variety of suitable communication interfaces. For example, I / O components include standard serial ports, parallel ports, universal serial bus (USB) ports, S-video ports, local area network (LAN) ports, and small computer system interface (SCSI) ports. A wired connection. Further, the I / O components may include, for example, wireless connections such as infrared ports, optical ports, Bluetooth® wireless ports, wireless LAN ports, and the like.

In one embodiment, the controller 80 may be connected to a network (not shown), which may include any intranet such as a local or wide area network, or an extranet such as the World Wide Web or the Internet. An interconnection network of the form The network can be physically implemented on a dedicated line, including a virtual private network (VPN), wireless or wired network.

Having described each of the individual components of one embodiment of the ice making machine 10, the manner in which the components interact and operate in this embodiment will now be described. During operation of the ice making machine 10 in a cooling cycle that includes both a sensible heat cycle and a latent heat cycle, the variable speed compressor 12 receives a substantially gaseous low pressure refrigerant from the evaporator 20 through the suction line 28d, pressurizes the refrigerant, The almost gaseous high-pressure refrigerant is discharged to the condenser 14 through the discharge line 28b. In the condenser 14, heat is removed from the refrigerant, and the substantially gaseous refrigerant condenses into a substantially liquid refrigerant. To help remove heat from the refrigerant, a variable speed condenser fan 15 may be arranged to blow air into the condenser 14.

In one embodiment, the substantially liquid high-pressure refrigerant exits the condenser 14 and then passes through a liquid line 28 c to a thermostat or electronic thermal expansion element 18 that introduces the evaporator 18 into the evaporator 20. Therefore, the pressure of the substantially liquid refrigerant is reduced. When the low-pressure expanded refrigerant passes through the tube of the evaporator 20, the refrigerant absorbs heat from the tube provided in the evaporator 20, and vaporizes as the refrigerant passes through the tube. A substantially gaseous low-pressure refrigerant is discharged from the outlet of the evaporator 20 through the suction line 28 d and introduced again into the inlet of the variable speed compressor 12.

Referring to FIG. 4, the method for carrying out the embodiment of the invention shown in FIG. 1 is described in detail. In the embodiment shown in FIG. 1, the variable operating point component is operated at a variable operating point during the cooling cycle. In step 400, a cooling cycle including both a sensible heat cooling cycle and a latent heat cooling cycle is initiated. In step 402, a water injection valve (not shown) is opened to supply water to the water reservoir 64. As water fills the sump 64, it enters the opening 98 of the air fitting 90 that traps air in the chamber 92. The air trapped in the chamber 92 and the air pipe 86 is slightly compressed by water and transmits the pressure increase to the pressure sensor 84. The pressure sensor 84 inputs this pressure as a voltage to the processor 82, and the processor 82 assigns a numerical value corresponding to a pressure scale that can be adjusted according to the water level of the water reservoir 64 to the voltage. The state of the cooling cycle may be adjusted according to the water level of the water reservoir 64. In this way, the controller 80 can monitor the water level of the sump 64 and control the variable operating point component accordingly.

When the desired ice making water level is reached in step 404, the controller 80 closes the water injection valve in step 406. In step 408, the variable speed water supply pump 62 operates at the initial speed and supplies water to the ice tray 60. In steps 410 and 412, variable speed compressor 12 and variable speed condenser fan 15 are operated at an initial speed to supply refrigerant at an initial mass flow rate. In one embodiment, the initial speed of the variable speed compressor 12 and variable speed condenser fan 15 is the maximum speed allowed by each component. During the sensible heat cooling cycle, the water supplied by the variable speed water supply pump 62 starts to cool when it contacts the ice tray 60, returns to the water reservoir 64 under the ice tray 60, and is made by the variable speed water supply pump 62. Recirculated to dish 60. When the cooling cycle enters the latent heat cooling cycle, the water stored in the ice tray 60 begins to form ice cubes.

In step 416, the control device 80 monitors the water level (x) based on the pressure input from the pressure sensor 84 and checks whether or not the water level of the water reservoir 64 has reached the iced water level. While the water level in the sump 64 exceeds the ice level, the controller 80 (at step 418) calculates the desired compressor speed (y) as a function of the water level (y = f (x)), ( Calculate the desired condenser fan speed (z) as a function of the water level (in step 420) (z = f (x)) and (in step 422) the desired feed pump speed (as a function of the water level (p = f (x))) p) is calculated. In step 424, the controller 80 then initializes the refrigerant mass flow rate by setting the variable speed compressor 12 to the desired compressor speed (y) at a speed less than the initial compressor speed (block 124). Change from refrigerant mass flow rate. At step 426, controller 80 also sets variable speed condenser fan 15 to the desired condenser fan speed (z) at a speed less than the initial condenser fan speed. In step 428, the controller 80 also sets the variable speed feed pump 62 to the desired pump speed (p) at a speed less than the initial pump speed. The variable speed water supply pump 62 continues to recirculate water from the water reservoir 64 onto the ice tray 60, and as the ice thickness of the ice tray 60 increases, the water level in the water reservoir 64 decreases.

The controller 80 repeats steps 416-428 based on the measurement of the water level in the sump 64, calculation of a new desired speed, and the identified cooling cycle condition until the water level in the sump 64 reaches the iced water level. Continue to set the desired speed to maintain a sufficient refrigerant mass flow to the evaporator 20 and a sufficient pressure drop through the thermal expansion element 18. When the water level in the sump 64 reaches the iced water level, the variable speed feed pump 62 is turned off (at step 430) and the hot gas valve 24 is opened (at step 432) so that warm high pressure gas is hot from the compressor 12. The gas enters the evaporator 20 through the gas bypass line 28a. Ice is collected by warming the ice tray 60 and melting the ice so that the formed ice is separated from the ice tray 60, and the ice is collected through a hole (not shown) and a lower container (for example, an ice bottle) (not shown). ) And temporarily stored in the container for later retrieval. In response to the ice collection, in step 434, an ice collection sensor switch that detects when ice is collected from the ice tray 60 is momentarily opened. In step 436, the hot gas valve 24 is then closed and the cooling cycle can be repeated. Although the steps are described herein in one order, it will be understood that other embodiments of the method may be performed in any order without departing from the scope of the invention.

As shown in FIG. 4, the ice making machine 10 may optionally operate the variable speed compressor 12 at a variable speed between step A and step B during ice collection. This will be described in more detail with respect to the embodiment of FIG. 10 elsewhere in this specification. Therefore, as shown in FIG. 9, in order to operate the variable speed compressor, the ice making machine 10 determines the temperature of the refrigerant entering the evaporator inlet 20a from the variable speed compressor 12 and the temperature of the refrigerant at the evaporator outlet 20b. Temperature sensors 120a and 120b for measuring each may be provided. This will be described in more detail elsewhere in this specification.

The ice making machine 10 may comprise any combination of variable and single operating point components (compressor, condenser fan, and / or feed pump) and a thermostat or electronic thermal expansion element. In a preferred embodiment, for example, icemaker 10 includes a variable speed compressor, a variable speed condenser fan, and a variable speed feedwater pump. Accordingly, the control device 80 changes the speeds of the variable speed compressor, the variable speed condenser fan, and the variable speed feed water pump based on the identified state of the cooling cycle. In another embodiment, for example, ice maker 10 comprises a variable speed compressor, a single speed condenser fan, and a single speed feed pump. Thus, the controller 80 changes the speed of the variable speed compressor based on the identified state of the cooling cycle, while operating the condenser fan and feed pump at a single speed. In yet another embodiment, for example, icemaker 10 includes a variable speed compressor, a variable speed condenser fan, and a single speed feed pump. Accordingly, the controller 80 operates the single speed feed pump at a single speed while varying the speed of the variable speed compressor and variable speed condenser fan based on the identified cooling cycle conditions. In yet another embodiment, for example, icemaker 10 includes a variable speed compressor, a single speed condenser fan, and a variable speed feedwater pump. Accordingly, the controller 80 operates the single speed condenser fan at a single speed while varying the speed of the variable speed compressor and variable speed feedwater pump based on the identified cooling cycle conditions. In yet another embodiment, for example, the ice maker 10 includes a variable speed compressor and a variable speed feed pump, but may not include a condenser fan (eg, a liquid-cooled ice maker). Therefore, the control device 80 changes the speeds of the variable speed compressor and the variable speed feed water pump based on the identified state of the cooling cycle. In yet another embodiment, for example, ice maker 10 may include a variable speed compressor and a single speed feed pump, but may not include a condenser fan. Thus, the controller 80 operates the single speed feed pump at a single speed while varying the speed of the variable speed compressor based on the identified cooling cycle conditions. In yet another embodiment, for example, ice maker 10 includes a single speed compressor, a variable speed condenser fan, and a single speed feed pump. Thus, the controller 80 operates the single speed compressor and single speed feed pump at a single speed while varying the speed of the variable speed condenser fan based on the identified cooling cycle conditions. In yet another embodiment, for example, icemaker 10 includes a single speed compressor, a variable speed condenser fan, and a variable speed feedwater pump. Thus, the controller 80 operates the single speed compressor at a single speed while varying the speed of the variable speed condenser fan and variable speed feed pump based on the identified cooling cycle conditions. In yet another embodiment, for example, icemaker 10 includes a single speed compressor, a single speed condenser fan, and a variable speed feedwater pump. Accordingly, the controller 80 operates the single speed compressor and single speed condenser fan at a single speed while varying the speed of the variable speed feedwater pump based on the identified cooling cycle conditions. In yet another embodiment, for example, the ice maker 10 may include a single speed compressor and a variable speed feed pump, but may not include a condenser fan. Accordingly, the controller 80 operates the single speed compressor at a single speed while varying the speed of the variable speed feed pump based on the identified cooling cycle conditions. Further, in some embodiments, for example, any combination of the above combinations may comprise an electronic thermal expansion valve. The controller 80 may control the electronic thermal expansion valve based on the identified cooling cycle state. The status of the identified cooling cycle includes the temperature of the refrigerant in the suction line 28d when the refrigerant exits the evaporator 20 (see FIGS. 9, 11 and 12), and the pressure of the refrigerant in the suction line 28d when the refrigerant exits the evaporator 20. (See FIGS. 9, 11 and 12), including the temperature of the water reservoir 64 (see FIG. 7), a sensor 70 (see FIG. 6) for monitoring ice formation in the ice tray 60 during the cooling cycle, etc. Not can be determined by various inputs.

In another embodiment, as shown in FIG. 5, the ice maker 510 incorporates the form of the inter-refrigerant heat exchanger 22 disposed in the liquid refrigerant line 28 c between the condenser 14 and the thermal expansion element 18. The inter-refrigerant heat exchanger 22 uses the warm liquid refrigerant exiting the condenser 14 to heat the cold refrigerant vapor exiting the evaporator 20. By heating the refrigerant vapor exiting the evaporator 20, any liquid refrigerant remaining in the vapor stream is vaporized. This helps to prevent liquid refrigerant from returning to the variable speed compressor 12. As those skilled in the art will appreciate, liquid refrigerant returning to the variable speed compressor 12 can damage the variable speed compressor 12. Furthermore, the cooling performance of the system can be enhanced by cooling the liquid refrigerant entering the evaporator 20 using the cold refrigerant vapor exiting the evaporator 20. Furthermore, the inter-refrigerant heat exchanger 22 appears to be useful for preventing flash gas. If refrigerant bubbles present in the liquid exiting the condenser 14 enter the expansion valve 18, the operation of the expansion valve may be hindered. By cooling the liquid refrigerant using the heat exchanger 22 before the liquid refrigerant enters the thermal expansion element 18, all bubbles can be removed, and proper operation of the thermal expansion element 18 is ensured. Finally, by raising the temperature of the refrigerant vapor, the suction line pipe downstream of the evaporator 20 is less likely to be frosted or condensed due to moisture from the surrounding air.

Accordingly, after leaving the condenser 14, the substantially liquid high-pressure refrigerant passes through the inter-refrigerant heat exchanger 22. The substantially liquid high-pressure refrigerant is converted into an almost gaseous low-pressure refrigerant that passes through the inter-refrigerant heat exchanger 22 in the opposite direction toward the inlet of the variable speed compressor 12 through the suction line 28d while passing through the inter-refrigerant heat exchanger 22. Convey heat. After the high-pressure liquid refrigerant leaves the inter-refrigerant heat exchanger 22, it arrives at the thermal expansion element 18, and the thermal expansion element 18 lowers the pressure of the substantially liquid refrigerant and introduces it into the evaporator 20. Since the low-pressure expanded refrigerant passes through the tube of the evaporator 20, it absorbs heat from the tube and vaporizes while passing through the tube provided in the evaporator 20. A substantially gaseous low-pressure refrigerant is discharged from the outlet of the evaporator 20, passes through the inter-refrigerant heat exchanger 22, and is reintroduced to the inlet of the variable speed compressor 12.

In another embodiment of the ice making machine 610 shown in FIG. 6, the pressure sensor 84, the airpipe 86, and the air fitting 90 are supplemented by a sensor 70 that monitors ice formation in the ice tray 60 during the cooling cycle. May be replaced. In various embodiments, the sensor may be any type of sensor adapted to monitor the ice thickness of the ice tray 60. In one embodiment, for example, sensor 70 may be an acoustic sensor that detects a change in ice thickness of ice tray 60 during a cooling cycle. An acoustic sensor for detecting the thickness of the ice formed is disclosed in US Application No. 13 / 368,814, “System, Apparatus, and Method for Ice Detection,” filed Feb. 8, 2012 by Rosenlund et al. This application is published as US Publication No. 2012/0198864, which is incorporated herein by reference in its entirety. The application proposes an acoustic transmitter that transmits sound waves at a constant frequency and an acoustic sensor that detects reflection of the transmitted sound waves. When the detected reflected wave reaches a certain expected amplitude, the system determines that the ice has reached the desired thickness. An acoustic sensor may be used to determine the ice thickness during the cooling cycle. As the cycle progresses, the thickness of the ice changes, and as a result, the reflected wave received by the acoustic sensor also changes. Controller 80 can then calculate and set the desired speed of the variable speed component based on the identified cooling cycle state. In another embodiment, for example, the sensor 70 may be a photographic optical sensor that detects a change in the ice thickness of the ice tray 60 during the cooling cycle. In yet another embodiment, for example, the sensor 70 can include an electromechanical float mechanism that detects the water level of the sump 64. In yet another embodiment, the sensor 70 may be an electrical probe placed near the ice tray 60, and when the ice reaches the desired thickness, the electrical circuit is terminated and the cooling cycle is terminated. In yet another embodiment, sensor 70 may identify the state of the cooling cycle based on the elapsed time since the start of the cooling cycle. The output of sensor 70 may be sent to controller 80, which controls the variable speed component (possible based on the identified cooling cycle status determined by the water level in sump 64 and the output of sensor 70. Change the speed of the variable speed compressor, variable speed condenser fan, and / or variable speed feed pump). In another embodiment, the ice maker includes a sensor 70 but does not include a pressure sensor 84, an airpipe 86, and an air fitting 90. In this embodiment, the output of sensor 70 may be sent to controller 80, which controls variable speed components (variable speed components) based on the identified cooling cycle conditions determined by sensor 70 output. The speed of the compressor, variable speed condenser fan and / or variable speed feed pump).

Variable Operating Point During Sensible Cooling In another embodiment shown in FIG. 7, for example, the variable operating point component of ice maker 710 can be used during a sensible cooling cycle and during a latent heat cooling cycle, during which both cooling loads are Operate at variable operating points as it fluctuates. By changing the operating point of the variable operating point component during the sensible cooling cycle in addition to the latent heat cooling cycle, the ice making machine 10 operates the variable operating point component at the maximum operating point, and supplies the supplied water. The variable operating point component can be decelerated to a lower operating point than the maximum operating point at the time of transition from the sensible heat cooling cycle to the latent heat cooling cycle within the cooling cycle. This can help to avoid flash freezing of the supplied water.

FIG. 7 shows some main components of this embodiment of the ice maker 710. The ice making machine 710 includes a variable speed compressor 12, a condenser 14 that condenses the compressed refrigerant vapor discharged from the variable speed compressor 12, a variable speed condenser fan 15, and heat that lowers the temperature and pressure of the refrigerant. An expansion element 18 and an evaporator 20 are provided. The thermal expansion element 18 may be a thermostat expansion valve or an electronic expansion valve. The ice maker 710 also includes an ice tray 60 that is thermally coupled to the evaporator 20. The ice tray 60 may be provided with a number of indentations (usually in the form of lattice cells) on the surface where water flowing over the surface can accumulate. The water is pumped from the sump 64 by the variable speed feed pump 62 and, when exiting the distribution manifold or tube 66 through the water supply line 63, collides with the ice tray 60, flows over the recess of the ice tray 60 and freezes. Become ice. The sump 64 may be located below the ice tray 60 and receives all the water falling from the ice tray 60 and the water is recirculated by the variable speed feed pump 62.

The ice making machine 710 may also include a temperature sensitive cylinder 26 that is disposed at the outlet of the evaporator 20 and controls the thermal expansion element 18. In other embodiments, when an electronic expansion valve 118 (see FIGS. 11 and 12) is used, the temperature sensor 25 and pressure transducer 29 may be used in place of the temperature sensitive cylinder (see FIGS. 11 and 12). . In this case, the temperature sensor 25 and the pressure converter 29 may provide the control device 80 with the temperature value and pressure value of the refrigerant in the suction line 28d, respectively. A temperature sensor 27 may be placed in the sump 64 to measure the temperature of the water in the sump 64. Further, when the ice reaches the desired thickness, the hot gas valve 24 is used to remove or collect ice cubes from the ice tray 60 by directing the warm refrigerant directly from the variable speed compressor 12 to the evaporator 20. It's okay. The ice maker 710 also includes an ice collection sensor switch (not shown) known in the art that detects when ice has fallen from the ice tray 60 so that the controller 80 can stop ice collection and begin making ice. Good. As described in more detail elsewhere herein, some form of refrigerant sequentially circulates through these components via lines 28a, 28b, 28c, 28d. The ice maker 710 may have other conventional components not described herein, including a water source, an ice bottle, and a power source.

In this particular embodiment, ice maker 710 also includes a controller 80 that is located remotely from evaporator 20 and water reservoir 64. The control device 80 includes a processor 82 that controls the operation of the ice making machine 710. In this embodiment, the controller 80 may also include or be coupled to the temperature sensor 27 and use the temperature sensor 27 to identify the state of the cooling cycle during the sensible heat cooling cycle. It's okay. Using the input from temperature sensor 27, processor 82 can determine the state of the cooling cycle based on the water temperature as the water is recirculated over the ice tray. As the water temperature falls during the sensible heat cooling cycle, the cooling load may also decrease, so the controller 80 calculates the operating point of the variable operating point component of the ice maker 710 based on the state of the cooling cycle with respect to the cooling load. Can be set. The controller 80 may also include or be coupled to the pressure sensor 84. The pressure sensor 84 may be used to identify the state of the cooling cycle during the latent heat cooling cycle of the ice maker 710 by correlating the water pressure in the sump 64 with the ice thickness of the ice tray 60. The pressure sensor 84 may be a monolithic silicon pressure sensor that can output a signal proportional to the pressure of the water in the water reservoir 64 to the processor 82. Using the output from the pressure sensor 84, the processor 82 can determine the state of the cooling cycle based on the amount of water turned to ice. As the ice thickness of the ice tray increases during the latent heat cooling cycle, the cooling load may decrease, so the controller 80 may change the variable operating point component of the ice maker 710 based on the state of the cooling cycle with respect to the cooling load. The operating point can be calculated and set. Therefore, the efficiency of the ice making machine 710 can be improved by using the variable speed compressor 12 that can change the mass flow rate of the liquid refrigerant based on the state of the cooling cycle. For example, the mass flow rate of the liquid refrigerant may decrease as the ice thickness of the ice tray 60 increases throughout the cooling cycle. The use of the pressure sensor 84 also allows the processor 82 to determine the appropriate time for the start of the ice collection cycle and to control the water injection and purge functions.

Referring to FIG. 8, the method of performing the embodiment of the invention shown in FIG. 7 is shown in detail. In this embodiment, the variable operating point component is operated at a variable operating point during the sensible cooling cycle and during the latent cooling cycle. In step 800, a cooling cycle including both a sensible heat cooling cycle and a latent heat cooling cycle is initiated. In step 802, a water injection valve (not shown) is opened and water is supplied to the water reservoir 64. Water fills the sump 64 and enters the opening 98 of the air fitting 90 trapping air in the chamber 92. The air trapped in the chamber 92 and the air pipe 86 is slightly compressed by water and transmits the pressure increase to the pressure sensor 84. The pressure sensor 84 inputs this pressure as a voltage to the processor 82. The processor 82 assigns a numerical value corresponding to a pressure scale that can be adjusted according to the water level of the water reservoir 64 to the pressure. The state of the cooling cycle may be adjusted according to the water level of the water reservoir 64. The controller 80 can thus monitor the water level in the sump 64 and can control the variable operating point components accordingly.

When the desired ice making water level is reached in step 804, the controller 80 closes the water injection valve in step 806. In step 808, the variable speed water supply pump 62 operates at the initial speed, and supplies water to the ice tray 60. In steps 810 and 812, the variable speed compressor 12 and variable speed condenser fan 15 are operated at an initial speed such that refrigerant is supplied at an initial mass flow rate. In one embodiment, the initial speed of the variable speed compressor 12 and variable speed condenser fan 15 is the maximum speed allowed by each component. During the sensible heat cooling cycle, the water supplied by the variable speed water supply pump 62 starts to cool by contacting the ice tray 60, returns to the water reservoir 64 under the ice tray 60, and is made by the variable speed water supply pump 62. Recirculated to dish 60.

In step 838, the temperature T _{w of the} recirculated water is then measured by the temperature sensor 27 to check whether the water temperature T _w exceeds a certain desired temperature. While the water temperature in the sump 64 exceeds the desired temperature, the controller 80 (at step 840) calculates the desired compressor speed (y) as a function of the water temperature (y = f (T _w )) ( Calculate the desired condenser fan speed (z) as a function of water temperature (in step 842) as a function of water temperature (z = f ( _Tw )) and (in step 844) the desired feed pump as a function of water temperature (p = f ( _Tw )) Calculate the velocity (p). In step 846, the controller 80 then changes the refrigerant mass flow rate from the initial refrigerant mass flow rate by setting the variable speed compressor 12 to a desired compressor speed (y) lower than the initial compressor speed. To do. In step 848, controller 80 also sets variable speed condenser fan 15 to a desired condenser fan speed (z) that is slower than the initial condenser fan speed. In step 850, the controller 80 also sets the variable speed feed pump 62 to a desired pump speed (p) that is slower than the initial pump speed. The variable speed water supply pump 62 continues to recirculate water from the water reservoir 64 onto the ice tray 60, and the water temperature of the water reservoir 64 decreases during the sensible heat cooling cycle.

The controller 80 repeats steps 838-850 until the water temperature in the sump 64 reaches the desired temperature indicating the transition of the cooling cycle to a latent heat cooling cycle, measuring the water temperature, calculating the new desired rate, and identifying the identified cooling. Based on the state of the cycle, continue to set the desired speed to maintain a sufficient refrigerant mass flow to the evaporator 20 and a sufficient pressure drop through the thermal expansion element 18. When the transition of the cooling cycle to the latent heat cooling cycle is initiated, the controller 80 may reduce the speed of the variable speed compressor to avoid instant water refrigeration.

When the cooling cycle enters the latent heat cooling cycle, the water stored in the ice tray 60 begins to form ice cubes. In step 816, the control device 80 monitors the water level (x) based on the pressure input from the pressure sensor 84, and checks whether or not the water level of the water reservoir 64 has reached the iced water level. While the water level in the sump 64 exceeds the ice level, the controller 80 (at step 818) calculates the desired compressor speed (y) as a function of the water level (y = f (x)) (step 818). Calculate the desired condenser fan speed (z) as a function of water level (z = f (x)) (in 820) and the desired feed pump speed (p) as a function of water level (p = f (x)) (in step 822) ). Controller 80 then changes the refrigerant mass flow rate from the initial refrigerant mass flow rate by setting variable speed compressor 12 to a desired compressor speed (y) that is slower than the initial compressor speed (in step 824). To do. In step 826, the controller 80 also sets the variable speed condenser fan 15 to a desired condenser fan speed (z) that is slower than the initial condenser fan speed. In step 828, the controller 80 also sets the variable speed feed pump 62 to a desired pump speed (p) that is slower than the initial pump speed. The variable speed water supply pump 62 continues to recirculate water from the sump 64 onto the ice tray 60, and as the ice thickness increases in the ice tray 60, the water level in the sump 64 decreases.

The controller 80 repeats steps 816-828 until the water level in the sump 64 reaches the ice level, based on the water level measurement, the new desired speed calculation, and the identified cooling cycle condition. The desired speed setting is continued to maintain a sufficient refrigerant mass flow rate to and a sufficient pressure drop through the thermal expansion element 18. When the water level in the sump 64 reaches the ice-collecting water level, the variable speed feed pump 62 is turned off (at step 830) and the hot gas valve 24 is opened (at step 832) so that warm high pressure gas is hot from the compressor 12. The gas flows through the gas bypass line 28 a and enters the evaporator 20. Thereby, ice is collected by warming the ice tray 60 and melting the ice so that the formed ice can be separated from the ice tray 60, and the ice is collected through a hole (not shown) in a lower container (eg, ice bottle). ) (Not shown), temporarily stored in the container, and later removed. Accordingly, in step 834, an ice collection sensor switch for detecting when ice is collected from the ice tray 60 is momentarily opened. Next, at step 836, the hot gas valve 24 is closed and the cooling cycle can be repeated. Although the steps described herein are described in one order, it will be understood that other embodiments of the method may be performed in any order without departing from the scope of the invention.

As shown in FIG. 8, the ice making machine 710 may optionally operate the variable speed compressor 12 at a variable speed between step A and step B during ice collection. This will be described in more detail elsewhere in this specification, for example with respect to the embodiment of FIG. Therefore, as shown in FIG. 9, the ice maker 710 measures the temperature of the refrigerant entering the evaporator inlet 20a from the variable speed compressor 12 and the temperature of the refrigerant at the evaporator outlet 20b in order to operate the variable speed compressor. Temperature sensors 120a and 120b may be provided. This is described in more detail elsewhere in this specification.

In another embodiment of the invention, the variable operating point component of the ice making machine 10 operates at a variable operating point as the cooling load changes during both the sensible heat cooling cycle and the latent heat cooling cycle. In the embodiment, the ice making machine 10 does not measure the temperature of the water in the water reservoir 64 for the purpose of determining whether the cooling cycle is a sensible heat cooling cycle or a latent heat cooling cycle. In this particular embodiment, a timer is used to determine whether the cooling cycle is a sensible cooling cycle or a latent cooling cycle based on the elapsed time. In one embodiment, for example, approximately 3 minutes after the start of the cooling cycle, the ice maker 10 enters the latent heat cooling cycle and the controller 80 begins changing the operating point of the variable operating point component. In another embodiment, for example, approximately 4 minutes after the start of the cooling cycle, the ice maker 10 enters a latent heat cooling cycle and the controller 80 begins changing the operating point of the variable operating point component. In another embodiment, for example, approximately 5 minutes after the start of the cooling cycle, the ice maker 10 enters a latent heat cooling cycle and the controller 80 begins changing the operating point of the variable operating point component. In another embodiment, for example, approximately 6 minutes after the start of the cooling cycle, the ice maker 10 enters a latent heat cooling cycle and the controller 80 begins changing the operating point of the variable operating point component. In another embodiment, for example, approximately 7 minutes after the start of the cooling cycle, the ice maker 10 enters a latent heat cooling cycle and the controller 80 begins changing the operating point of the variable operating point component. Thus, in some embodiments, the controller 80 begins changing the operating point of the variable operating point component of the ice making machine 10 during a latent cooling cycle between about 3 minutes and about 7 minutes after the start of the cooling cycle. obtain.

In yet another embodiment of the invention, the variable operating point component of ice maker 10 operates at a variable operating point as the cooling load changes both during the sensible heat cooling cycle and during the latent heat cooling cycle. In the embodiment, the ice making machine 10 does not measure the temperature of the water in the water reservoir 64 for the purpose of determining whether the cooling cycle is a sensible heat cooling cycle or a latent heat cooling cycle. In this particular embodiment, a timer is also used to determine whether the cooling cycle is a sensible cooling cycle or a latent cooling cycle based on a percentage of the total cooling cycle time. In one embodiment, for example, when about 10 percent of the total time of the entire cooling cycle has elapsed, the ice maker 10 enters a latent heat cooling cycle and the controller 80 begins changing the operating point of the variable operating point component. . In another embodiment, for example, when about 20 percent of the total time of the entire cooling cycle has elapsed, the ice maker 10 enters a latent heat cooling cycle and the controller 80 begins changing the operating point of the variable operating point component. To do. In another embodiment, for example, after approximately 30 percent of the total cooling cycle time has elapsed, the ice maker 10 enters a latent heat cooling cycle and the controller 80 begins changing the operating point of the variable operating point component. To do. In another embodiment, for example, after about 40 percent of the total cooling cycle time has elapsed, the ice maker 10 enters a latent heat cooling cycle and the controller 80 begins changing the operating point of the variable operating point component. To do. In another embodiment, for example, when about 50 percent of the total time of the entire cooling cycle has elapsed, the ice maker 10 enters a latent heat cooling cycle and the controller 80 begins changing the operating point of the variable operating point component. To do. In another embodiment, for example, when about 60 percent of the total time of the entire cooling cycle has elapsed, the ice maker 10 enters a latent heat cooling cycle and the controller 80 begins changing the operating point of the variable operating point component. To do. In another embodiment, for example, after approximately 70 percent of the total cooling cycle time has elapsed, the ice maker 10 enters a latent heat cooling cycle and the controller 80 begins changing the operating point of the variable operating point component. To do. In another embodiment, for example, when approximately 80 percent of the total cooling cycle time has elapsed, the ice maker 10 enters a latent heat cooling cycle and the controller 80 begins changing the operating point of the variable operating point component. To do. In another embodiment, for example, after approximately 90 percent of the total cooling cycle time has elapsed, the ice maker 10 enters a latent heat cooling cycle and the controller 80 begins changing the operating point of the variable operating point component. To do. Thus, in some embodiments, the controller 80 can control the operating point of the variable operating point component of the ice maker 10 during a latent heat cooling cycle between about 10 percent and about 90 percent of the total time of the entire cooling cycle. Changes can begin.

Variable Operating Point During Ice Collection In another embodiment shown in FIG. 9, for example, the variable operating point component of ice maker 910 may have a sensible heat cooling cycle, a latent heat cooling cycle, and a cooling load during Operate at variable operating points as it changes. In particular, the variable speed compressor 12 can be operated at various speeds during the ice collection cycle, and serves to collect ice formed in the ice tray 60 without excessive melting.

FIG. 9 shows some main components of this embodiment of the ice maker 910. The ice making machine 910 reduces the temperature and pressure of the variable speed compressor 12, the condenser 14 that condenses the compressed refrigerant vapor discharged from the variable speed compressor 12, the variable speed condenser fan 15, and the refrigerant. The thermal expansion element 18 and the evaporator 20 are provided. The thermal expansion element 18 may be a thermostat expansion valve or an electronic expansion valve. The ice maker 910 also includes an ice tray 60 that is thermally coupled to the evaporator 20. The ice tray 60 may be provided with a number of indentations (usually in the form of lattice cells) on the surface, and water flows over the surface and accumulates in the indentations. The water is pumped from the sump 64 by the variable speed feed pump 62, passes through the water supply line 63, exits the distribution manifold or tube 66, collides with the ice tray 60, flows over the recess of the ice tray 60, and freezes. Become ice. The sump 64 may be located below the ice tray 60 and receives all the water falling from the ice tray 60 and the water is recirculated by the variable speed feed pump 62.

Further, when the ice reaches a desired thickness, the hot gas valve 24 is used to transfer the warm refrigerant from the variable speed compressor 12 via the hot gas bypass line 28 directly to the evaporator 20 from the ice tray 60 to the ice cube. May be removed or iced. The ice making machine 910 also includes a temperature sensor 120a that measures the temperature of the warm refrigerant that enters the evaporator inlet 20a from the hot gas valve 24, and a temperature sensor 120b that measures the temperature of the refrigerant that exits the evaporator outlet 20b. Although temperature sensors 120a, 120b are shown in the context of ice maker 910, in order to operate variable speed compressor 12 during the ice collection cycle without departing from the scope of the invention, temperature sensors 120a, 120b are: Those skilled in the art will appreciate that any of the ice maker embodiments described herein may be included. The ice making machine 910 also includes an ice collection sensor switch (not shown) known in the art that detects when ice has fallen from the ice tray 60 so that the controller 80 can stop ice collection and start making ice. It's okay. As described in more detail elsewhere herein, some form of refrigerant circulates through these components in turn via lines 28a, 28b, 28c, 28d. The ice maker 910 may have other conventional components not described herein, such as a water source, ice bottle, and power source.

In this particular embodiment, ice maker 910 also includes a controller 80 that is remote from evaporator 20 and sump 64. The control device 80 includes a processor 82 that controls the operation of the ice making machine 910. In this embodiment, the controller 80 may also include or be coupled to the temperature sensors 120a, 120b that may be used to monitor the ice collection cycle. Using the inputs from the temperature sensors 120a, 120b, the processor 82 is suitable for operating the variable speed compressor 12 to assist in picking ice from the ice tray 60 without unleashing excessive ice. Can be determined. When the hot gas valve 24 is opened, an initial quantity of high temperature, high pressure refrigerant is directed to the evaporator inlet 20a via the hot gas bypass line 28a. This hot gaseous refrigerant then flows through the tortuous tubes of the evaporator 20 to warm the ice tray 60. Then, the ice in the ice tray 60 starts to melt.

However, depending on the speed of the variable speed compressor 12 and / or the type of refrigerant used in the ice making machine, the temperature in the evaporator 12 and the ice making tray 60 may increase, causing the ice on the ice making tray 60 to melt excessively. . Excessive ice melting can cause the temperature of the hot CO ₂ gas entering the evaporator 20 through the inlet 20a to reach 300 degrees Fahrenheit when using carbon dioxide (CO ₂ ) as the refrigerant, especially It becomes a problem. As a result of excessive melting of the ice, it becomes smaller than the desired ice and / or becomes melting ice, which is less efficient due to the energy used to form the ice and the waste of energy used to collect the ice. Therefore, it would be beneficial to be able to operate the variable speed compressor 12 at variable speeds during ice collection depending on the refrigerant temperature and / or the rate of change of refrigerant temperature at the inlet 20a and / or outlet 20b of the evaporator 20. .

Referring to FIG. 10, the method of carrying out the embodiment of the invention shown in FIG. 9 for operating a variable speed compressor at a variable speed during an ice collection cycle is shown in detail. FIG. 10 shows only the operation of the ice making machine 910 during the ice collection cycle. Although this method is described with respect to an ice maker 910, the ice maker of any embodiment described herein may operate the variable speed compressor 12 at a variable speed during an ice collection cycle. Those skilled in the art will appreciate. For example, when the ice maker enters ice collection by opening the hot gas valve 24 (see step 432 in FIG. 4 and step 832 in FIG. 8), the ice maker is at A with any variable speed compression during ice collection. You may proceed to the operation of the machine 12. In step 1002, the temperature _{T IN} of the refrigerant entering the evaporator inlet 20a from the variable speed compressor 12 through the hot gas bypass line 28a is measured by the temperature sensor 120a. Based on the measured refrigerant temperature T _IN , in step 1004, the controller 80 calculates the desired compressor speed (y) as a function of refrigerant temperature (y = f (T _IN )). In step 1006, the controller 80 then sets the variable speed compressor 12 to the desired compressor speed (y). In step 1008, the temperature change rate (Δ の_OUT ) of the refrigerant exiting the evaporator outlet 20b is measured by the temperature sensor 120b. In step 1010, the controller 80 monitors the rate of change of the refrigerant temperature (ΔΤ _OUT ) exiting the evaporator outlet 20b to determine whether the rate of change exceeds a desirable upper limit. When the rate of change exceeds the desired upper limit, this means that the temperature of the refrigerant flowing through the evaporator 20 is too high and the ice in the ice tray 60 melts excessively. Therefore, if the rate of change exceeds the desired upper limit, in step 1012, the controller 80 reduces the temperature of the refrigerant entering the evaporator inlet 20a by reducing the speed of the variable speed compressor 12, thereby making the ice tray 60. Reduce excessive melting of ice.

If the rate of change does not exceed the desired upper limit, in step 1014, the controller 80 monitors the rate of change in temperature of the refrigerant exiting the evaporator outlet 20b (ΔΤ _OUT ) to determine whether the rate of change is below the desired lower limit. To decide. If the rate of change is below the desired lower limit, this means that the temperature of the refrigerant flowing through the evaporator 20 is too low and is longer than the desired ice collection time. Therefore, if the rate of change is below the desired lower limit, in step 1016, the controller 80 increases the temperature of the refrigerant entering the evaporator inlet 20a by increasing the speed of the variable speed compressor 12, thereby increasing the ice tray 60. Increase the ice melting above to achieve the desired length of ice collection. However, if the rate of change exceeds the desired lower limit and is within the desired lower limit and upper limit, then in step 1018, the controller 80 maintains the speed of the variable speed compressor 12 set in step 1006. This helps to reduce excessive ice melting during ice collection and maintain the desired length of ice collection time.

In step 1020, the control device 80 monitors whether or not the ice collection sensor switch is momentarily opened to indicate that ice has been collected from the ice tray 60. If the ice collection sensor switch does not open, the process of changing the speed of the variable speed compressor 12 returns to step 1202 and repeats until the ice collection sensor switch indicates that ice has been collected. In step 1020, when the ice collection sensor switch is momentarily opened to indicate that ice has been collected from ice tray 60, the process ends and at B returns to the method shown in FIGS. In an alternative embodiment, for example, the ice maker may not include an ice collection sensor and may use the refrigerant temperature measured at the evaporator outlet 20b by the temperature sensor 120b to determine when the ice collection is over. For example, a temperature of about 45 degrees Celsius to about 50 degrees Celsius measured at the evaporator outlet 20b (eg, about 45 degrees Celsius, about 46 degrees Celsius, about 47 degrees Celsius, about 48 degrees Celsius, about 49 degrees Celsius, about 49 degrees Celsius, (About 50 degrees) typically indicates that ice has been collected from ice tray 60. Although the steps described herein are described in one order, it will be understood that other embodiments of the method may be performed in any order without departing from the scope of the invention.

Accordingly, the variable speed compressor 12 may operate at various speeds during the ice collection cycle. For example, the variable speed compressor 12 may operate at a low speed at the beginning of the ice collection cycle, increase speed during the ice collection cycle, and may decrease at the end of the ice collection cycle. In other embodiments, for example, the variable speed compressor 12 may operate at a high speed at the beginning of the ice collection cycle, and then slow down and at a low speed at the end of the ice collection cycle.

As described herein, in various embodiments of the ice making machine 10, the variable speed compressor 12 is sampled at a first speed during a sensible heat cooling cycle and at a second speed during a latent heat cooling cycle. A third speed may be operated during the ice cycle. Desirably, the first speed is higher than the second speed, and the second speed is higher than the third speed. Accordingly, the variable speed compressor 12 may be operated at a high speed during the sensible heat cooling cycle, at a medium speed during the latent heat cooling cycle, at a low speed during the ice collection cycle. However, it will be appreciated that the variable speed compressor 12 may operate at higher or lower speeds during the sensible cooling cycle, the latent cooling cycle, and the ice collection cycle, respectively. That is, the second speed may be higher than the first speed and / or the third speed, or the third speed may be higher than the first speed and / or the second speed.

In yet another embodiment of the ice making machine 10, for example, the variable speed compressor 12 is in a first speed range, in a latent heat cooling cycle, in a second speed range, in an ice collection cycle during a sensible heat cooling cycle. You may drive in the third speed range. Desirably, the speed in the first speed range is higher than the speed in the second speed range, and the speed in the second speed range is higher than the speed in the third speed range. Accordingly, the variable speed compressor 12 may operate at a high speed range during the sensible heat cooling cycle, at a medium speed range during the latent heat cooling cycle, and at a low speed range during the ice collection cycle. In various embodiments, for example, the first, second, and / or third speed ranges may overlap at least partially. That is, a part of the first speed range may be included in at least a part of the second speed range, and a part of the second speed range is included in at least a part of the third speed range. Well and / or part of the first speed range may be included in at least part of the third speed range.

Electronic Thermal Expansion Valve In combination with any of the above embodiments, an electronic thermal expansion valve that can be controlled by the control device 80 as shown in FIGS. 11 and 12 may be used. Accordingly, various embodiments of ice makers 1110, 1210 include a variable speed compressor 12, a condenser 14 that condenses the compressed refrigerant vapor discharged from the variable speed compressor 12, and a variable speed condenser fan 15. The electronic thermal expansion valve 118 for lowering the temperature and pressure of the refrigerant and the evaporator 20 may be provided. The electronic thermal expansion valve 118 may be controlled by the controller 80 according to the temperature and pressure of the refrigerant in the suction line 28d as the refrigerant exits the evaporator 20. The temperature sensor 25 may measure the temperature of the refrigerant in the suction line 28d when the refrigerant exits the evaporator 20, and the pressure converter 29 measures the pressure of the refrigerant in the suction line 28d when the refrigerant exits the evaporator 20. May be measured. The temperature sensor 120b shown in FIG. 9 may be used instead of the temperature sensor 25. The temperature and pressure of the refrigerant may be input to the control device 80 so that the control device 80 can determine the saturation temperature of the refrigerant. Accordingly, by measuring the temperature and pressure of the refrigerant in the suction line 28d, the controller 80 controls the size of the opening of the electronic thermal expansion valve 118 to reduce or eliminate the liquid refrigerant exiting the evaporator 20. can do. Thus, the electronic thermal expansion valve 118 can be controlled to raise and / or maintain the refrigerant temperature in the suction line 28d as the refrigerant exits the evaporator 20 above the refrigerant saturation temperature. This is known as superheat temperature control. In this case, the superheat temperature is a temperature difference between the refrigerant temperature in the suction line 28d and the saturation temperature of the refrigerant (that is, superheat temperature = temperature of the refrigerant in the suction line 28d−saturation temperature of the refrigerant).

Thus, a novel method and apparatus for an ice maker having variable operating point components has been shown and described. However, it will be apparent to those skilled in the art that many changes, variations, and modifications, as well as other uses and applications, of the subject matter of the invention can be made. All such changes, variations and modifications as well as other uses and applications that do not depart from the spirit and scope of the invention are deemed to be within the scope of the invention, and the invention is only limited by the claims that follow. Limited.

Claims (20)

An ice making machine that forms ice during the cooling cycle,
A variable speed compressor, a condenser, and an evaporator, wherein the variable speed compressor, the condenser, and the evaporator are in fluid communication with one or more refrigerant lines; Or flow through multiple refrigerant lines
An ice tray thermally coupled to the evaporator;
A water supply pump for supplying water to the ice tray;
A detection device adapted to identify the state of the cooling cycle;
A controller adapted to control the speed of the variable speed compressor based on the identified state of the cooling cycle;
An ice making machine. The controller is adapted to operate the variable speed compressor at a first speed during a sensible heat cooling cycle, at a second speed during a latent heat cooling cycle, at a second speed, at a third speed during an ice collection cycle. The ice maker according to claim 1, wherein the first speed is faster than the second speed, and the second speed is faster than the first speed. The ice maker of claim 1, wherein the detection device is adapted to measure a water level in a sump. The ice maker of claim 1, wherein the detection device is adapted to measure the temperature of the water in the sump. The ice maker of claim 1, wherein the detection device is adapted to monitor the ice thickness of the ice tray. One of the one or more refrigerant lines includes a suction line between the condenser and the evaporator, and the ice maker further comprises an electronic thermal expansion valve in fluid communication with the suction line. Item 2. The ice making machine according to Item 1. And further comprising a temperature sensor and a pressure transducer, wherein the temperature sensor is adapted to measure the temperature of the refrigerant in the suction line, and the pressure transducer is adapted to measure the pressure of the refrigerant in the suction line. Adapted,
The ice making machine of claim 6, wherein the controller is adapted to control the electronic thermal expansion valve based on the measured temperature and pressure of the refrigerant in the suction line. The variable speed condenser fan according to claim 1, further comprising a variable speed condenser fan, wherein the controller is adapted to further control the speed of the variable speed condenser fan based on the identified state of the cooling cycle. Ice machine. The said feed pump is a variable speed feed pump, and the controller is further adapted to control the speed of the variable speed feed pump based on the identified state of the cooling cycle. The ice machine described. A variable speed condenser fan, wherein the feed pump is a variable speed feed pump, and the controller is configured to determine the speed of the variable speed condenser fan and the variable speed based on the identified state of the cooling cycle. The ice maker of claim 1, further adapted to control the speed of the feed pump. The one or more refrigerant lines include a suction line between the condenser and the evaporator, and the ice maker further comprises an electronic thermal expansion valve in fluid communication with the suction line. The ice making machine according to 10. And further comprising a temperature sensor and a pressure transducer, wherein the temperature sensor is adapted to measure the temperature of the refrigerant in the suction line, and the pressure transducer is adapted to measure the pressure of the refrigerant in the suction line. Adapted,
The ice maker of claim 11, wherein the controller is adapted to control the electronic thermal expansion valve based on the measured temperature and pressure of the refrigerant in the suction line. A first temperature sensor that measures an inlet temperature of the refrigerant that enters the evaporator; and a second temperature sensor that measures an outlet temperature of the refrigerant that exits the evaporator, and the control device measures the measured temperature. The ice maker of claim 1, wherein the ice maker is adapted to change a speed of the variable speed compressor during an ice collection cycle depending on inlet and / or outlet refrigerant temperature. A thermal expansion element disposed in fluid communication between the condenser and the evaporator; and an inter-refrigerant heat exchanger disposed in fluid communication between the condenser and the thermal expansion element. The inter-refrigerant heat exchanger is further disposed in fluid communication between the evaporator and the variable speed compressor to remove heat of the refrigerant discharged from the condenser assembly. The ice making machine according to claim 1. In a method of controlling an ice making machine that forms ice during a cooling cycle, the ice making machine comprises a variable speed compressor, a condenser, and an evaporator, the variable speed compressor, the condenser, and the evaporation The vessel is in fluid communication with one or more refrigerant lines, the refrigerant flows through the one or more refrigerant lines, and the ice maker is an ice tray thermally coupled to the evaporator; A water supply pump for supplying water to the ice tray, a detection device adapted to identify the state of the cooling cycle, and controlling the speed of the variable speed compressor based on the identified state of the cooling cycle. A control device adapted to:
Identifying the state of the ice making machine cooling cycle;
Calculating a desired compressor speed of the variable speed compressor based on the identified state of the cooling cycle;
Changing the mass flow rate of the refrigerant by changing the speed of the variable speed compressor to the desired compressor speed;
Including the method. The ice making machine further includes a first temperature sensor that measures an inlet temperature of the refrigerant entering the evaporator, and a second temperature sensor that measures an outlet temperature of the refrigerant exiting the evaporator, and the control device Is adapted to change the speed of the variable speed compressor during an ice-collecting cycle in response to the measured inlet refrigerant temperature and / or outlet refrigerant temperature,
Calculating a desired condenser fan speed of the variable speed condenser fan based on the measured inlet refrigerant temperature and / or outlet refrigerant temperature;
Changing the speed of the variable speed condenser fan to the desired condenser fan speed;
16. The method of claim 15, further comprising: The ice maker further comprises a variable speed condenser fan, and the controller is adapted to further control the speed of the variable speed condenser fan based on the identified state of the cooling cycle;
Calculating a desired condenser fan speed of the variable speed condenser fan based on the identified state of the cooling cycle;
Changing the speed of the variable speed condenser fan to the desired condenser fan speed;
16. The method of claim 15, further comprising: The feed pump is a variable speed feed pump, and the controller is further adapted to control the speed of the variable speed feed pump based on the identified state of the cooling cycle;
Calculating a desired feed pump speed of the variable speed feed pump based on the identified state of the cooling cycle;
Changing the speed of the variable speed feed pump to the desired feed pump speed;
16. The method of claim 15, further comprising: The ice maker further comprises a variable speed condenser fan, the feed pump is a variable speed feed water pump, and the controller is configured to control the variable speed condenser fan based on the identified state of the cooling cycle. Further adapted to control the speed and the speed of the variable speed feed pump;
Calculating a desired condenser fan speed of the variable speed condenser fan based on the identified state of the cooling cycle;
Calculating a desired feed pump speed of the variable speed feed pump based on the identified state of the cooling cycle;
Changing the speed of the variable speed condenser fan to the desired condenser fan speed;
Changing the speed of the variable speed feed pump to the desired feed pump speed;
16. The method of claim 15, further comprising: In an ice maker that forms ice during the cooling cycle,
A variable speed compressor, a condenser, and an evaporator, wherein the variable speed compressor, the condenser, and the evaporator are in fluid communication with one or more refrigerant lines; Or an ice maker that flows through multiple refrigerant lines,
An ice tray thermally coupled to the evaporator;
A water supply pump that supplies water to the ice tray, which accumulates in the ice tray and freezes into ice;
A controller adapted to operate the variable speed compressor at a first speed during a sensible cooling cycle, at a second speed during a latent heat cooling cycle, at a second speed, at a third speed during an ice-collecting cycle; , Wherein the first speed is faster than the second speed, and the second speed is faster than the first speed.

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